Unsigned DIVide

NAME
	DIVU, DIVUL -- Unsigned divide

SYNOPSIS
	DIVU.W	<ea>,Dn     32/16 -> 16r:16q
	DIVU.L	<ea>,Dq     32/32 -> 32q      (68020+)
	DIVU.L	<ea>,Dr:Dq  64/32 -> 32r:32q  (68020+)
	DIVUL.L	<ea>,Dr:Dq  32/32 -> 32r:32q  (68020+)

	Size = (Word, Long)

FUNCTION
	Divides the unsigned destination operand by the unsigned
	source operand and stores the unsigned result in the destination.

	The instruction has a word form and three long forms. For the
	word form, the destination operand is a long word and the source
	operand is a word. The resultant quotient is placed in the lower
	word of the destination and the resultant remainder is placed in the
	upper word of the destination. The sign of the remainder is the
	same as the sign of the dividend.

	In the first long form, the destination and the source are both
	long words. The quotient is placed in the longword of the destination
	and the remainder is discarded.

	The second long form has the destination as a quadword (eight bytes),
	specified by any two data registers, and the source is a long word.
	The resultant remainder and quotient are both long words and are
	placed in the destination registers.

	The final long form has both the source and the destination as long
	words and the resultant quotient and remainder as long words.

FORMAT
	In the case of DIVU.W:
	~~~~~~~~~~~~~~~~~~~~~                              <ea>
	----------------------------------------=========================
	|15 |14 |13 |12 |11 |10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
	|---|---|---|---|-----------|---|---|---|-----------|-----------|
	| 1 | 0 | 0 | 0 | REGISTER  | 0 | 1 | 1 |    MODE   | REGISTER  |
	-----------------------------------------------------------------

	"REGISTER" indicates the number of data register.

	In the case of DIVU.L and of DIVUL.L:
	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~               <ea>
	-----------------------------------------=========================
	|15 |14 |13 |12 |11 |10  | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
	|---|---|---|---|---|----|---|---|---|---|-----------|-----------|
	| 0 | 1 | 0 | 0 | 1 | 1  | 0 | 0 | 0 | 1 |    MODE   | REGISTER  |
	|---|-----------|---|----|---|---|---|---|-----------|-----------|
	| 0 |Dq REGISTER| 0 |SIZE| 0 | 0 | 0 | 0 | 0 | 0 | 0 |Dr REGISTER|
	------------------------------------------------------------------

	"Dq REGISTER" indicates the number of data register for destination
	operand. This register first contains 32 bits of low weight of
	dividend, and after the value of quotient on 32 bits.

	"SIZE" specifies if dividend is on 32 or 64 bits:
	0-> 32 bits dividend placed in Dq.
	1-> 64 bits dividend placed in Dr:Dq.

	"Dr REGISTER" indicates the number of data register for destination
	operand. This register first contains 32 bits of upper weight of
	dividend if "SIZE" = 1, and after the value of rest on 32 bits.

	If Dr and Dq represents the same register, only quotient on 32 bits
	is put in Dq.

	<ea> field specifies source operand, allowed addressing modes are:

	--------------------------------- -------------------------------
	|Addressing Mode|Mode| Register | |Addressing Mode|Mode|Register|
	|-------------------------------| |-----------------------------|
	|      Dn       |000 |N° reg. Dn| |    Abs.W      |111 |  000   |
	|-------------------------------| |-----------------------------|
	|      An       | -  |    -     | |    Abs.L      |111 |  001   |
	|-------------------------------| |-----------------------------|
	|     (An)      |010 |N° reg. An| |   (d16,PC)    |111 |  010   |
	|-------------------------------| |-----------------------------|
	|     (An)+     |011 |N° reg. An| |   (d8,PC,Xi)  |111 |  011   |
	|-------------------------------| |-----------------------------|
	|    -(An)      |100 |N° reg. An| |   (bd,PC,Xi)  |111 |  011   |
	|-------------------------------| |-----------------------------|
	|    (d16,An)   |101 |N° reg. An| |([bd,PC,Xi],od)|111 |  011   |
	|-------------------------------| |-----------------------------|
	|   (d8,An,Xi)  |110 |N° reg. An| |([bd,PC],Xi,od)|111 |  011   |
	|-------------------------------| |-----------------------------|
	|   (bd,An,Xi)  |110 |N° reg. An| |    #data      |111 |  100   |
	|-------------------------------| -------------------------------
	|([bd,An,Xi]od) |110 |N° reg. An|
	|-------------------------------|
	|([bd,An],Xi,od)|110 |N° reg. An|
	---------------------------------

RESULT

	X - Not affected
	N - See below.
	Z - Set if the quotient is zero, cleared otherwise. Undefined if
	    overflow or divide by zero occurs.
	V - Set if overflow occurs, cleared otherwise. Undefined if divide by
	    zero occurs.
	C - Always cleared.

	Notes:
	1. If divide by zero occurs, an exception occurs.
	2. If overflow occurs, neither operand is affected.

	According to the Motorola data books, the N flag is set if the
	quotient is negative, but in an unsigned divide, this seems to
	be impossible.

SEE ALSO
	DIVS MULS MULU